Terminal structure of FRD (Fast Recovery Diode) chip, preparation method thereof and FRD chip provided with terminal structure

Abstract

The invention provides a terminal structure of an FRD (Fast Recovery Diode) chip, a preparation method thereof and an FRD chip provided with the terminal structure. The FRD chip is provided with a substrate and an epitaxial wafer arranged on the substrate. The FRD chip comprises the terminal structure and an active structure, wherein the terminal structure is arranged in the epitaxial wafer around the active structure of the FRD chip, and the extending direction of the substrate towards the epitaxial wafer is the depth direction. The terminal structure comprises a terminal voltage withstanding ring, a terminal stop ring, wherein the terminal voltage withstanding ring is arranged in the epitaxial wafer; the terminal stop ring is arranged in the epitaxial wafer at the side, which is away from the active structure, of the terminal withstanding ring, the substrate, the epitaxial wafer and the terminal stop ring are identical in the type of doping ions, and the doping ions of the terminal withstanding ring and doping ions of the epitaxial wafer are inversion ions. The number of the voltage withstanding ring is set to be one, so that the terminal structure is enabled to be greatly reduced in occupied area compared with the scheme of a voltage dividing ring in the prior art, and the terminal voltage withstanding ring has enough voltage withstanding performance. Therefore, the conductive capacity of the chip is improved, and the cost of manufacturing the terminal voltage withstanding ring is reduced.

Description

technical field [0001] The invention relates to the field of FRD chips, in particular to a terminal structure of an FRD chip, a preparation method thereof and an FRD chip having the same. Background technique [0002] Fast recovery diode (FRD) has the advantages of good switching performance, short reverse recovery time, and large forward current. It is often used in parallel with three-terminal power switching devices in power electronic circuits as a high-frequency, high-current freewheeling diode or rectifier At present, it has been widely used in induction cooker, power supply, frequency conversion household appliances, frequency conversion welding machine, electric vehicle and other products. According to the characteristics of the fast recovery diode, it is mainly used in the high-voltage field, so it is usually necessary to adopt terminal protection technology at the chip boundary of the fast recovery diode, that is, to set the terminal area to reduce the surface elec...

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Problems solved by technology

[0003] The main purpose of the present invention is to provide a terminal structure of FRD chip, its preparation method and FRD chip with it, so as to solve the problem of how to improve the conductivity of the chip while ensuring the withstand voltage performance of the device

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